Question:
(1)   In the VF and PEA algorithm it states adrenaline is to be given every 3-5 min but in practice every 4 min (every 2 loops). In the scenario of PEA as the initial rhythm with adrenaline given in the first loop, what happens if after the second loop the casualty goes into VF/VT? Do we follow the VF guideline and give adrenaline at the end of loop 2 before the third shock (which gives a delay of 6- 8 min from last adrenaline dose) or do we give adrenaline at 4 min which would be before the 2nd shock? - this would lead to adrenaline and amiodarone being given before the 4th shock.
 
Answer:
During CPR, adrenaline is given every 3 –5 min  – this reflects its half-life. When switching from the non-shockable to the shockable side of the algorithm, the next dose of adrenaline will be given before the first or the second shock depending on when adrenaline was last given.
 

Question:
(2)   In the case of pulseless VT, after completing 2 min of CPR, if there is no change in the VT waveform should defibrillation be attempted without checking the pulse?
 
Answer:
If there is no change in the appearance and rate of the waveform, deliver a shock without checking for a pulse.
 

Question:
(3)   If adrenaline is not ready to be given before a shock and a change in rhythm is noted on the monitor despite immediate resumption of chest compressions, should adrenaline be given at this stage?
 
Answer:
If an organised rhythm is seen clearly soon after shock delivery (perhaps while pausing the compressions for ventilation), do not give adrenaline until the pulse check after 2 min of CPR confirms the absence of a pulse.
 

Question:
(4)   After a precordial thump is given should the rescuer immediately start chest compressions without checking the rhythm or the pulse as in defibrillation?
 
Answer:
The rhythm and, if indicated, the pulse, should be checked after a precordial thump.
 

Question:
(5)   If, during the non-shockable loop there is suspected or evident change in the rhythm to a shockable rhythm, should the rescuer stop chest compressions and confirm this or continue until the 2 min loop is completed?
 
Answer:
Complete the 2 min CPR before confirming the rhythm and delivering a shock as indicated. This is covered on page 37 of the ALS manual.
 

Question:
(6)   On page 110 of the ALS manual, cardioversion energy levels have now been separated into levels used for a broad complex tachycardia or atrial fibrillation and levels used for atrial flutter or narrow complex tachycardia. When you add the possibility of either monophasic or biphasic waveforms and then state: “if the first shock does not terminate the arrhythmia, give up to two more shocks of increasing energy up to the maximum setting of the defibrillator” - we consider this guidance to be potentially confusing.
 
Answer:
The ALS Subcommittees of the RC(UK) and the ERC discussed at length the topic of energy levels during cardioversion. Given the varying waveforms and energy levels it was impossible to come up with a single set of energies that was both supported by data and did not appear to favour any particular manufacturer. The wording on page 110 has been carefully crafted to be as simple as possible. The sensible advice is for course centres to determine their own energy levels based on the guidance given on page 110 and on the make of their own defibrillators.
 

Question:
(7)   The Resuscitation Guidelines 2005 (page 47) indicate that pulse checks in PEA should be undertaken at the end of the 2 min cycle only if the ECG changes and organised electrical activity is seen. However, the ALS manual (page 36) indicates that if organised activity is seen after 2 min CPR, the pulse should be checked; it gives the impression that this needs to occur after each cycle. This contradicts the guidelines and goes against the principle of not interrupting CPR for pulse checks. Which is correct?
 
Answer:
While writing the ALS manual it was realised that the guidelines are misleading on this point. In the presence of PEA, it is entirely possible for a pulse to become palpable without any change in waveform. Thus, at the end of 2 min CPR, if there is an organised rhythm, check the pulse.
 

Question:
(8)   Is there any indication to give a second dose of amiodarone if VF/VT persists after the first dose of amiodarone and further shocks?
 
Answer:
Following the first three shocks and amiodarone 300 mg, there are no data on when or if additional amiodarone is beneficial. A second dose of amiodarone 150 mg is often given to treat tachyarrhythmias and, on this basis, it is reasonable to give an additional 150 mg if VF/VT remains unresponsive to further shocks.
 

Question:
(9)   If VF is witnessed and monitored, and a shock is delivered almost immediately, is it reasonable to check the rhythm and the pulse instead of going directly into chest compressions and giving 2 min of CPR?
 
Answer:
On the ALS course we want instructors to be consistent and teach that chest compressions are resumed immediately without checking the rhythm. Obviously, if the patient shows signs of life (e.g., movement or normal breathing), stop chest compressions and confirm return of spontaneous circulation.
 

Question:
(10)   If VF is witnessed and monitored, and the first shock is delivered almost immediately, is it reasonable to continue to give up to three stacked shocks as would have been done using the 200 guidelines?
 
Answer:
The ALS manual indicates that single shocks should be used even if the VF/VT cardiac arrest is witnessed and monitored.
 

Question:  (Added July 2006)
(11)   When using mechanical ventilators with intubated patients, I have noticed that during asynchronised CPR that the pressure relief valve regularly ‘blows’. Is there a recommended pressure setting for mechanical ventilators for use ONLY during CPR?
 
Answer:
When ventilation is undertaken without interrupting chest compressions the airway pressure is inevitably going to be intermittently extremely high (when inspiration coincides with the compression phase). On these occasions the airway pressure is bound to be higher than the pressure relief valve on an automatic ventilator and there will inevitably be some leak even at the maximum setting on most pressure relief valves. There is no recommended setting (most will leak at 40 - 60 cm H₂O), but it makes sense to put the valve at its highest possible setting. There are two options during CPR:

1. Revert to manual ventilation;  
   
2. Ignore the leak - as ventilation is usually excessively high during the CPR, there will probably still be adequate ventilation despite the leak.

Question:  (Added April 2007)
(12)   The 2005 ERC guidelines state that during adult CPR, when using supplemental oxygen, tidal volumes of 500- 600 ml should be given, whereas the ALS manual indicates a volume of 400- 600ml.   Which is correct?
 
Answer:
The ALS manual and 2005 ERC Guidelines both indicate that a tidal volume of 6-7 ml kg^-1 is an appropriate volume for ventilating the lungs with supplemental oxygen during CPR. In practice, this volume will not be measured; therefore, deliver a volume that produces ‘visible chest movement’. Larger tidal volumes (10 ml kg^-1) are recommended during expired-air ventilation. When calibrating manikins, manufacturers will have to take into consideration scenarios with and without supplemental oxygen. For these reasons, appropriate ranges for tidal volumes may lie anywhere between 400-800 ml.
 

Question:  (Added July 2008)
(13)   Can calcium gluconate be used instead of calcium chloride during the current shortage of the latter?
 
Answer:
Yes - as long as equivalent doses are given (i.e., 3 times more gluconate (226 micromol/ml) than chloride (680 micromol/ml)), the peak rise in ionised calcium and the time to peak is exactly the same. Contrary to some published statements, liberation of ionised calcium from calcium gluconate does not depend on conversion by the liver.¹
Reference 
1. Martin T, Kang Y, Robertson K, Virji M, Marquez J.  Ionization and Hemodynamic Effects of Calcium Chloride and Calcium Gluconate in the absence of hepatic function.  Anesthesiology 73:62-65, 1990
 
 
 
 
 

	© Resuscitation Council (UK)  2008   This page last updated: 29 July 2008